There exists many types of computer device where the user interface is controlled by touch. That is, activation of functions and objects is responsive to user input made by way of the user actually touching a particular object displayed on the screen, and thereby selecting that object.
Most commonly, that touch is by a user's finger. In computer devices which are designed to be portable, very often the screen area which is available for the object to be selected can be quite small, and as a consequence the objects can be quite close to each other. This can make it difficult for a finger (which may be relatively large as compared with the size of the object) to accurately select one particular object amongst a group of closely adjacent objects.
One particular context in which this arises is in the context of a computer game where a game board is displayed to a user which has adjacent selectable objects, for example in the form of letter tiles. In one game, the mechanic of the game is that a user should select a set of tiles in succession and thereby form words. The successful delivery of this game depends on the game application being able to accurately determine which of the letter tiles a user has selected. There can be some cases where a finger rests on the boundary of two or more tiles and this is difficult for the game application to reliably select which of the tile is intended to be selected by the user.
One such game is a game called Alphabetty available via the royal game website (www.royalgames.com). In this game, a user must select adjacent letters to form a word. When a word has been formed, the letters are automatically removed from the screen and letter tiles above the removed letters drop down. New letter tiles are provided to the screen from above to replenish the gaps now left by the tiles which have dropped down. In that sense, the game is a match-3 game similar to Candy Crush. When constructing a game application for installation on a mobile device with a smaller screen, the above referenced technical problems manifest themselves.